I remember seeing a slave flash trigger project for your setup in Everyday Practical Electronics in April 2006, check this website http://www.epemag.wimborne.co.uk/projects2006.html and look at Aprils projects, you may need to contact them via email for a copy of the project details and the PCB is available from there order service. I professional photographer friend of mine had remote flash units triggered by the camera flash so no connection to your camera was neccesary.

 

Hope this helps